BE 2.2 GALLONS PER MINUTE AT 60 PSI. SCREWS OR FASTENING MEANS WHICH EXTEND INTO THE DUCT. SANITARY BUILDING DRAIN DOWN 4. EXHAUST DUCTS SHALL BE EOUIPED WITH A BACKDRAFT DAMPER. WATER SUPPLY LINE UP FROM PUMP ROOM 5. EXHAUST DUCTS SHALL HAVE SMOOTH INTERIOR SURFACES WITH JOINTS RUNNING IN THE DIRE